Various oil materials such as silicone oil, ester oil, hydrocarbon oil are used for cosmetics. They are used depending on their characteristics and the purpose. For example, silicone oil has characteristics such as good usability including a light feeling and non-stickiness, excellent water repellency, and high safety. Each of these oil materials is blended in cosmetics solely or in a combined form.
In emulsion type cosmetics blended with oil materials and water, surfactant is generally used. When the oil material is silicone oil, it is difficult to obtain an emulsion with good stability even though an emulsifier such as polyoxyalkylene fatty acid ester is used. Accordingly, it has been proposed a method to use polyoxyalkylene modified organopolysiloxane (polyether modified silicone), which has good compatibility with silicone oils (PATENT LITERATURE 1 to PATENT LITERATURE 5).
In order to enhance the compatibility with oils, including not only silicone oil but also other oil materials, it has also been proposed a method to use organopolysiloxane having a long-chain alkyl group and a polyoxyalkylene group as well as straight chain silicone as an emulsifier (PATENT LITERATURE 6 and PATENT LITERATURE 7). The emulsified composition containing silicone oil or other oil materials, however, still have a problem for providing excellent emulsion stability and ensuring temporal stability. Moreover, emulsified cosmetics blended with polyether modified silicone still suffer from stickiness after being applied, and needs to achieve affective emulsifying property in a smaller blending amount.
In addition, in the case that powders are included in a cosmetic, it is necessary that the powders have excellent dispersion stability without causing changes such as agglomeration of powders. Alternatively, a polyether-modified silicone which has a dendrimer-like branched silicone structure has been known, but the structure of the dendrimer silicone moiety is so unique that a complicated process is necessary in its preparing process, and this causes higher production cost. Moreover, this polyether-modified silicone is difficult to obtain as a single product, and has lower reactivity due to its bulky structure (PATENT LITERATURE 8).